Crystal structure and superconducting properties of Sc₅Ir₆Sn₁₈

Sc₅Ir₆Sn₁₈ crystallizes with a split variant of the Tb₅Rh₆Sn₁₈ structure type (space group I4₁/acd, [Formula: see text] [Formula: see text], [Formula: see text] [Formula: see text]). DFT calculations confirmed the instability of the structural arrangement with the fully occupied and unsplit crystallographic sites. High quality single crystals were grown from a Sn melt. Sc₅Ir₆Sn₁₈ is a diamagnetic metal showing a superconducting transition at a critical temperature [Formula: see text] K. The relatively low critical magnetic field [Formula: see text] 3.2 T as well as the obtained values of the specific heat ratio [Formula: see text] and energy-gap ratio [Formula: see text] suggest this system to be a weakly coupled BCS-like superconductor.